1. Field of the Invention
The present invention relates to a valve device, and more particularly to a valve device, such as a relief valve, a check valve, or the like, having a solid engaging structure for making an air tight or a water tight seal.
2. Description of the Prior Art
Typical air or water flowing systems or facilities are required to install one or more check valves or relief valves therein, for pressure relieving purposes or for controlling the flowing direction of the air or water.
For example, U.S. Pat. No. 1,055,437 to Aldridge discloses one of the typical relief valves for spraying purposes, and comprises a semispherical valve to be rested loosely on a valve seating.
However, the semispherical valve may not be forced to solidly engage with the valve seating, such that the engagement between the semispherical valve and the valve seating may not be formed into a solid air tight or water tight seal or engagement.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional valve devices.